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science chapter 1 section 1 and 3 chapter 2 section 3
Question | Answer |
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Chemistry | is the study of the properties of matter and how matter changes |
matter | is anything that has mass and takes up space |
substance | is a single kind of matter that is pure, meaning it always has a specific make up |
physical properties | a characteristic of a pure substance that can be observed without changing it into another substance …..how matter looks,feels,smells,sounds and tastes |
chemical properties | a characteristic of a pure substance that describes its ability to change into different substances….tells how matter can change into new kinds of matter…example: wood catching fire and burning |
element | a pure substance that cannot be broken down into any other substance by chemical or physical means |
atom | the basic particle from which all elements are made |
Chemical bond | a force of attraction between two atoms |
Molecule | groups of two or more atoms held together by chemical bonds |
compound | a pure substance made of two or more elements chemically combined in a set ratio |
chemical formula | shows the elements in compounds and the ratio of atoms |
mixture | is made of two or more substances |
Heterogeneous formula | you can see the different parts |
Homogenous mixture | so evenly mixed that you can't see the different parts |
solution | an example mixture of a homogenous mixture |
physical change | is any change that alters the form or appearance of matter but does not make any substance in the matter into a different substance |
chemical change | a change in matter that produces one or more new substances |
law of conservation of mass | the fact that matter can not be made or destroyed |
Energy | is the ability to do work or cause change |
Temperature | is a measure of the average energy of random motion of particles of matter |
thermal energy | is the total energy of all the particles in an object |
endothermic change | change in which energy is taken in |
exothermic change | releases energy |
pressure | is the force of outward push divided by the area of the walls of the container Pressure = force/area |
Boyle's law | When the pressure of a gas at constant temputure is increased, the volume of the gas decreases. W.hen the pressure is decreased the volume increases |
Charles's law | when the temperature of a gas increases at a constant pressure its volume increase. When the temputure of the gas is decreased at constant pressure, its volume decreases. |